(a) Field of the Invention
This invention relates to a focal plane shutter wherein each of a front blade group and rear blade group consists of a plurality of opaque laminae so as to make an exposure when each blade group runs in the vertical direction and more particularly to a focal plane shutter of a type wherein a front blade group and rear blade group are maintained in an exposure aperture covering position except when they move to make an exposure.
(b) Description of the Prior Art
A focal plane shutter of this type has been developed for the purpose of preventing light from leaking on a film and reducing the height of a camera and has been already practiced. Generally, in this type of focal plane shutter, a pair of a blade driving member and blade operating member are provided so that the opening and closing motion of each of the front blade group and rear blade group may be shared by the driving member and operating member. Therefore, these driving member and operating member must be biased in the directions opposite to each other. According to a conventional mechanism, the driving member and operating member are biased by respective independent springs and therefore there has been a defect that the formation is complicated.